When my friend Katy told me that she’s attending Jazzercise classes multiple times a week, I admit it — I giggled.

Jazzercise seems as old as time itself. I imagined a class full of women wearing 1980s-style G-string leotards and neon leg warmers.

But Katy, a young mother, assures me this is not the case. She says Jazzercise classes are fun, and the music is current and hip. She even works out to Lady Gaga tunes.

Well, I had to see this for myself.

I contacted Laura Salmonson, a Jazzercise instructor for two years who holds classes in San Ramon. She invited me to a Thursday morning class.

Salmonson is petite, extremely fit and has been working out for years. She used to take body sculpting and aerobics classes before discovering Jazzercise about six years ago. Once she took a class, she was hooked. No more having to take two classes for what she gets in Jazzercise.

“The Jazzercise slogan is ‘Take it, love it, teach it’ and that’s what I did. It’s so true,” she says.

Founded in 1969 by Judi Sheppard Missett, Jazzercise is not a shrinking violet in the 21st century. In fact, Missett reports that the Jazzercise company has seen its best years financially in this decade. There are 8,000 franchises all over the world, and 675 classes are offered weekly in the Bay Area.

“We’re cooking,” says the 66-year-old founder, who takes and leads classes every day. “When I started this 40 years ago, it was the philosophy that exercise should be fun, enjoyable and effective. We’ve really stayed true to that philosophy since the beginning.”

That doesn’t mean Jazzercise hasn’t changed in 40 years, Missett says. She keeps up on all the fitness trends and studies. She comes up with 90 new pieces of choreography every 10 weeks. She also has an entire department at Jazzercise headquarters in Carlsbad that is in touch with current trends in music and dance, even discovering new tunes before popular culture does. So Jazzercise — an aerobics program that incorporates jazz dance, resistance training, Pilates, yoga, and cardio box movements — isn’t just playing the sound track to “Flashdance” ad nauseam.

“If we were still doing what we did back in 1985, the fact is we wouldn’t still be here. The reason we’re still here is because we’re trying new things,” Missett says. For example, over the years the aerobics section of the workout has been lengthened, and Jazzercise has been incorporating weights, balls and resistance bands.

There were about a dozen women in my class, and although some were older than me, the ages ranged from women in their early 20s to women in their 60s. They teased one another about rivaling baseball teams — A’s vs. Giants — before class, then quickly turned to the front of the class when Salmonson commanded attention.

For the first 20 minutes or so, we started a warm-up, marching in place like many exercise classes do. We then started shaking our hips, stretching our legs and arms, and moving to the music.

Then it got hyper.

To the beat of songs from the cast of “Glee” and Justin Bieber, we kicked, danced, punched and hopped around until our heart rates elevated and sweat poured down our faces. Salmonson called out the moves before we did them and worked out with us, smiling the whole time.

I am hopelessly uncoordinated, but I followed Salmonson’s moves and used the woman in front of me as a guide for each step. And once I accepted the beat of whatever song we were listening to, I found the moves to be easy to do but still challenging for my body. I knew I was getting a real workout, and I didn’t have to be a dancer to do so.

The final 20 minutes of the hour-long class focused on weight training and mat work. I felt my abs tighten as I did crunches and kicked my feet. The weights grew heavy in my hands as I moved my arms up, down and around.

I was surprised the hour burned by as quickly as it did.

By the end of class, I realized that Jazzercise was not as old-timey as I thought. Though not as personally focused as other classes I’ve been to — there was no personal correction of my stance, form or knee bends — I still felt I got a healthy workout.

Missy Brennan of Danville says that she goes to Jazzercise regularly because “I feel like I am a backup dancer or something.”

And although nobody would call me to dance backup for Lady Gaga any time soon, I may try Jazzercise again at least for that “I’ve had a good workout” feeling.

THE BASICS

MAKE SURE YOU BRING: A bottle of water, a yoga mat, small hand weights and a towel to sop up your sweat.DRESS IN: Loose exercise pants, a snug top and shoes you feel comfortable working out in.BEST SUITED FOR: People who are interested in aerobics, light strength training and stretching.DON’T TAKE THIS CLASS IF: You have heart or cardiovascular problems. Many moves can be modified for people with joint, knee or back issues. Talk to the instructor before class.EXPERT SAYS: Jan Richards, a Northern California physical therapist at Kaiser Permanente Oakland, says that before you start any aerobics class, you should get clearance from your doctor. Next, observe the class to see what physical requirements are needed. Then, she says, take it slowly.AVERAGE CALORIES BURNED: Jazzercise officials say you can burn up to 600 calories per hour-long class, depending on your level of exertion. COST: Monthly fees average $45 for unlimited classes. Many areas charge an initiation fee, but Salomon does not.FOR MORE INFO: Find classes at www.jazzercise.com or call 800-348-4748. Take a Jazzercise class in San Ramon through Laura Salmonson at 17011 Bollinger Canyon Road. Call Salmonson at 925-683-6329.

About this series: “Trimming Trends” is an occasional feature on the various fitness crazes offered in the Bay Area. Features writer Laura Casey tries out a different class each month. If you have a suggestion of a class she should take, call her at 925-952-2697 or e-mail lcasey@bayareanewsgroup.com.

A transit village with apartments, retailers, restaurants and a hotel is rising in Milpitas next to The Great Mall, close to light rail and the under-construction BART station. It’s one of several Silicon Valley projects sprouting up near transit.